liblttng-ust-libc-wrapper/lttng-ust-pthread.c

   1 /*
   2  * Copyright (C) 2013  Mentor Graphics
   3  *
   4  * This library is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU Lesser General Public
   6  * License as published by the Free Software Foundation; either
   7  * version 2.1 of the License, or (at your option) any later version.
   8  *
   9  * This library is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12  * Lesser General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU Lesser General Public
  15  * License along with this library; if not, write to the Free Software
  16  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301 USA
  17  */
  18
  19 #define _GNU_SOURCE
  20 #include <lttng/ust-dlfcn.h>
  21 #include <pthread.h>
  22
  23 #define TRACEPOINT_DEFINE
  24 #define TRACEPOINT_CREATE_PROBES
  25 #include "ust_pthread.h"
  26
  27 static __thread int thread_in_trace;
  28
  29 int pthread_mutex_lock(pthread_mutex_t *mutex)
  30 {
  31         static int (*mutex_lock)(pthread_mutex_t *);
  32         int retval;
  33
  34         if (!mutex_lock) {
  35                 mutex_lock = dlsym(RTLD_NEXT, "pthread_mutex_lock");
  36                 if (!mutex_lock) {
  37                         if (thread_in_trace) {
  38                                 abort();
  39                         }
  40                         fprintf(stderr, "unable to initialize pthread wrapper library.\n");
  41                         return EINVAL;
  42                 }
  43         }
  44         if (thread_in_trace) {
  45                 return mutex_lock(mutex);
  46         }
  47
  48         thread_in_trace = 1;
  49         tracepoint(ust_pthread, pthread_mutex_lock_req, mutex);
  50         retval = mutex_lock(mutex);
  51         tracepoint(ust_pthread, pthread_mutex_lock_acq, mutex, retval);
  52         thread_in_trace = 0;
  53         return retval;
  54 }
  55
  56 int pthread_mutex_trylock(pthread_mutex_t *mutex)
  57 {
  58         static int (*mutex_trylock)(pthread_mutex_t *);
  59         int retval;
  60
  61         if (!mutex_trylock) {
  62                 mutex_trylock = dlsym(RTLD_NEXT, "pthread_mutex_trylock");
  63                 if (!mutex_trylock) {
  64                         if (thread_in_trace) {
  65                                 abort();
  66                         }
  67                         fprintf(stderr, "unable to initialize pthread wrapper library.\n");
  68                         return EINVAL;
  69                 }
  70         }
  71         if (thread_in_trace) {
  72                 return mutex_trylock(mutex);
  73         }
  74
  75         thread_in_trace = 1;
  76         retval = mutex_trylock(mutex);
  77         tracepoint(ust_pthread, pthread_mutex_trylock, mutex, retval);
  78         thread_in_trace = 0;
  79         return retval;
  80 }
  81
  82 int pthread_mutex_unlock(pthread_mutex_t *mutex)
  83 {
  84         static int (*mutex_unlock)(pthread_mutex_t *);
  85         int retval;
  86
  87         if (!mutex_unlock) {
  88                 mutex_unlock = dlsym(RTLD_NEXT, "pthread_mutex_unlock");
  89                 if (!mutex_unlock) {
  90                         if (thread_in_trace) {
  91                                 abort();
  92                         }
  93                         fprintf(stderr, "unable to initialize pthread wrapper library.\n");
  94                         return EINVAL;
  95                 }
  96         }
  97         if (thread_in_trace) {
  98                 return mutex_unlock(mutex);
  99         }
 100
 101         thread_in_trace = 1;
 102         retval = mutex_unlock(mutex);
 103         tracepoint(ust_pthread, pthread_mutex_unlock, mutex, retval);
 104         thread_in_trace = 0;
 105         return retval;
 106 }